Magnetic field coupling is inherently an imperfect process. The imperfection causes “leakage.” Specifically, the interstitial and uncoupled parasitic field element that exists as an inductive energy storage device (LI2) enables leakage energy. For example, power converters often have leakage magnetic fields which cause undesirable voltage excursions and loss in efficiency. Existing techniques to contain the leakage magnetic fields typically have substantial transactional loss due to the use of resistive or reactive elements.